Suicide is the leading cause of premature death in schizophrenia. Ten to fifteen percent of individuals with schizophrenia commit suicide and 3O-4O percent make suicide attempts. Suicidal behavior is devastating to the individual as well as the family and community. The goals of this study are: 1) to describe suicidal behavior in patients with schizophrenia; 2) to compare individuals with schizophrenia who have made a suicide attempt (high-risk group) with individuals with schizophrenia who are nonattempters (low-risk group) with respect to sex, race, clinical state, aggression, impulsivity depression, premorbid functioning demoralization, serotonin measures, family history of suicidal behavior and substance use; and 3) to collect baseline data for a prospective follow-up study in the future. These variables were selected because they have been found to be related to suicidal behavior in other patient groups and may be indicators of reduced ability to inhibit suicidal behavior. The variables were also selected because it is feasible to measure them in clinical settings making them accessible for clinical assessment and intervention studies. Information obtained from this study will be used to develop clinical interventions targeted to individuals with schizophrenia. No published study exists where all these major domains have been assessed simultaneously in a group of individuals with schizophrenia who are at high-risk for suicidal behavior in order to determine their relative contributions towards that behavior. This study will be the first phase in a future prospective study of suicidal behavior in schizophrenia. Participants will be inpatients on the Schizophrenia Research Units at the New York State Psychiatric Institute and Creedmoor Psychiatric Center. Standard structured interviews, observational rating scales and self-report measures will be administered to assess suicidal behavior, clinical state, aggression, impulsivity depression, premorbid adjustment, family history and substance use. Genetic and biochemical measures of serotonin are also obtained. Long-term objectives of this research are to identify variables that contribute to suicidal behavior in order to facilitate the development of assessments and interventions specific for individuals with schizophrenia.